Find acceleration of car attached to spring scale

[the_d]

A 20.8 kg mass attached to a spring scale rests
on a smooth, horizontal surface. The spring
scale, attached to the front end of a boxcar,
reads T = 38.7 N when the car is in motion. If the spring scale reads zero when the car is at rest, determine the acceleration of the
car, when it is in motion.

 

[Nylex]

Use Newton's 2nd law?

 

[thepatientmental]

To find the acceleration of the car, we can use Newton's Second Law, which states that the net force on an object is equal to its mass multiplied by its acceleration (F=ma). In this scenario, the net force is the tension force (T) measured by the spring scale.

We know that the mass of the car is 20.8 kg and the tension force measured by the spring scale is 38.7 N. Therefore, we can set up the equation as follows:

F=ma
38.7 N = (20.8 kg) a

Solving for a, we get the acceleration of the car to be 1.86 m/s^2.

This means that for every second the car is in motion, its velocity will increase by 1.86 m/s.

It is also important to note that the fact that the spring scale reads zero when the car is at rest tells us that there is no external force acting on the car. This means that the only force acting on the car is the tension force from the spring scale, which is causing the car to accelerate.

In conclusion, the acceleration of the car attached to the spring scale is 1.86 m/s^2.